material_ui package migration

[jt274]

Migrate to the new material_ui package which has been decoupled from the flutter framework in flutter 3.47.0: https://flutter.dev/blog/whats-new-in-flutter-3-47

Require dart >=3.5.0 and flutter >=3.47.0

Checklist

• I have bumped the version in pubspec.yaml
• I have added an entry in changelog.md for the new pubspec version
• (if applicable) I have added "Closes #1234" to this termplate to automatically close related issues.
• (not required if no sensible change has been made eg: Localization) I have added tests that prove my fix is effective or that my feature works.

[jt274]

@cedvdb Once this is released I will submit a similar PR for the phone_form_field package that depends on this version.

[cedvdb]

@jt274

Thanks. I merged this too fast, so this was reverted. Two pipelines have failed.

Could you resubmit with those fixed please ?

The first one because there are new issues with flutter analyze:

  info • Library names are not necessary. Remove the library name • lib/flutter_country_selector.dart:1:9 • unnecessary_library_name
   info • Missing type annotation. Try adding a type annotation • lib/flutter_country_selector.dart:29:10 • strict_top_level_inference
   info • Missing type annotation. Try adding a type annotation • lib/flutter_country_selector.dart:66:10 • strict_top_level_inference
   info • Missing type annotation. Try adding a type annotation • lib/src/country_selector_base.dart:102:3 • strict_top_level_inference
   info • Missing type annotation. Try adding a type annotation • lib/src/country_selector_base.dart:108:3 • strict_top_level_inference
   info • Missing type annotation. Try adding a type annotation • lib/src/widgets/_search_box.dart:35:21 • strict_top_level_inference

The second one during publish to pub dev:

Package validation found the following error:
* line 5, column 1 of lib/src/localization/generated/country_selector_localization.dart: This package does not have flutter_localizations in the `dependencies` section of `pubspec.yaml`.
    ╷
Sorry, your package is missing a requirement and can't be published yet.
For more information, see: https://dart.dev/tools/pub/cmd/pub-lish.
  5 │ import 'package:flutter_localizations/flutter_localizations.dart';
    │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ╵
    
    ````

[jt274]

@cedvdb I resubmitted this in #46